I'm still interested in one of these, I just need the extra cash but one of these days I hope to purchase one for my FC before they're no longer available.
Brian posted a great example of why one of these are needed especially if you're reaching high RPMs.
http://rotarycarclub.com/rotary_foru...d=1#post220404
Luckily no major damage or injury was caused from that (that I know of) but could've happened.